Tachometer.



ED JUNE 25, 1907.

mi N E T .A D.. kM N ml N .A R Mgnm RMD BMM \.0 BMW EAM a .Tm W M f n 5 A 1 10P @4094/0 I f f. w

3. e .s C A a Application Filed Ooi/)lier 4, 1906,

1*; ha@ reliiiiuii m iiuziruiueui's -iuriiig s led er wiue'i'y und ie fle-- u'ieil le iudirme the mie oi sgi "l ur ruf pidiiy :u uhirh heel er eyliiidei l\,'- ug, being; explicable with equal :ulvzuiiige u ei-k. he iiished. in. .ui-whine imei@ zuid. u ihe wheels vehicles, euteiuuhilesI rmui trains., om.

unimi, Finishes 0it :'z which there .fire uw )mmh-l .i ue wel fleeing a iu iuiheiu if' whiuh :ire rifeperi'ii'ely reinweieg-d :il *iheir @uds hy upeu porfis i. ih@- ehxuuher 1'. lhere is a rulfiahle screw pump r? 1'() which .uiuiimi is impfu'ied from. the moving element Whose speed it is desired. u1 ascertain. This serew fits mieuralely in. 'die cluuuher l1 su hfi', when it iS related, il. will cause ai fluid ul proper consiel'onuy zuid cmupusiiiuu iu eireulale through the chaluburs i) zuid c. Arranged. iu the Chamber c and iii he axial line thereof, there is :i guide rod e upon which. is adapted to edile :1. iiozu. er pisieu e. This pieten is held yieldinglif and. uernuilly (when he screw :it rest) against n, .stop (ff on the rod c by means (if a helical spring ff". The external diameter of the piston is lesslluui the interim] diameter of the cl'izunbei' su that a. proper amount of fluid mai-jy' escupe past ii, When the screw is ro mind in the direction indicated by the arrow, ily forcee the liquid outward through the puri Z1 into the chamber c pieun t0 the right in said Chamber until the pri-Sure el" zhe spring e oil-seis or euuui'erbalances the upon he piston reiuaii'istatenary se lou the screw rom'les ai im even speed. The

he xaisreiv (f'ilindriczil :uid moves the i pressure of ihe `liquid 5 where.- j

Fa-cened Yuna 25, 1907.

Scrivi n. 337

wher sidi r; my ne Suid le :ich upm but h he j. 'um uullzmeeusiy wid i-uiiseuuemly ihui'e a. quivi( und ausw irai-ie response hf ihe pieiwu m any Slight i uidu'me zii/eur makin" .i' possible to aus well high the if/.whim ui' the pieton d. e wall i Chai'z'nber c is l :md iu the slot,

shaft which is arranged iu axial *reinem with 'the aerei' shufb and which is jeuriiz'iled in zi sleeie er hushiugff', screwed iut@ zin exleueieri u," :il` (me end of the Upon its ou er end, said shaft carries Casing.

:i small wheel'. iphery eiwhicll is shod with rubber iis indicated atf. The hul) @if the Wheel ie pointed and cut away so thaty it ,may he inserted iu an aperture in the axis of rotating part le measure its Speed of rotation. The iiuier end of the Shaft/'is e11- larged. and eueheted to reeeiiezithimhle g i which islield hy e., spring y," against the hearing seat (Z3 $0- preveui the leakage of he fluid l hy er pas the drive sluiftji A. Simili piu g2 is 1| driven through -he ytliinihle se 'iluiiis'ends i projeet into slots (uol shown) in me end of the. drive Shaft; and the ihiuihle ilzself is re CeSSed so that the slotted end of the screw Shaft d lua-y eugge said pin as shown in Fig.

Along the.

.uuu g imei.; ilu-,ifiislon /to "eine: V Viure oi ci." d :ir-

`ling` the juuriuiled in zi j IOC IOS

A plug h.

2. By this construction, power is transmitted from the shaft fte' the screw shaft d and at the same time the thimble is free to adjust itself against the face of the bearing d3 to form a close ruiming joint.

The end of the chamber a is closed by the bearing d2 r. .id by a screw plug d3. Similar screw plugs may be used to close the ends of the chamber c. For convenience, however, the plugs h h are driven friction-ti ht into lace, the rod e which is pinned to t e block being screwed into a threaded recess in the It will be understood that the packing rings, as indicated at i, will also be inserted between the flanges on the plugs and lheends of the casing to prevent the escape of A tachometer or speedometer constructed as herein described, possesses numerous advantages due to its compact arrangement and simplicity of construction, which contribute to render the instrument accurate and convenient. It has a minimum number f working parts, thus greatly reducing the chance of error due to wear of the parts. Furthermore, the instrument, as illustrated, may be manufactured economically so as to produce it at a normal cost.

Having thus explained the nature of the said invention and described a way of constructing and using the same, although. without attempting to set forth all of the forms in which it may be made, or all of the modes of its use, I declare that what I claim is 1. A tachometer comprising a casing containing parallel chambers, connected at their ends by ports, and adapt( i to receive a Huid, a rotary screw in one of said chambers adapted to be rotated by the element whose speed is to be measured to effect a circulation of fluid through. said chambers, a spring pressed piston in the other chamber, and means by which the position of the piston may be indicated.

2. A tachometer comprising a casing containing parallel cylindrical chambers connected at their ends by open ports, a screw fitting in one of said chambers and adapted to be rotated by the element whose speed is to be measured to eflect the circulation ofthe fluid through said chamber and ports, a guide rod in the other of said chambers, a piston adapted to slide on said rod and being of less diameter than the chamber to permit the fluid to escape past it, a spring bearing against said piston, and means by which the position of the piston may be observed.

3. A tachometer comprising a casing containing parallel cylindrical chambers connectedD at their ends by open ports, a screw fitting in one of said chambers and adapted to be rotated by the element whose speed is to be measured to effect the circulation of the fluid through said chambers and erts, and a spring pressed piston in the ot er of said chambers adapted to be moved against the pressure of the spring by the pressure of the fluid, and less in diameter than the chamber to permit the fluid to flow past it, there being in the last-mentioned chamber a glazed slot to permit observation of the position of the piston.

4. A tachometer comprising a casing containing parallel chambers, connected at their ends by ports, and adapted to receive a fluid, a rotary screw in one of said chambers adapted t'o be rotated by the element whose speed is to be measured to efl'ect a circulation of fluid through said chambers, a spring pressed piston in the other chamber, means by which the position ol' the piston may be indicated, a shaft for transmitting power to the screw alined therewith, a bearing for said screw, and a spring pressed. thilnble adjacent said bearing, substantially as described, to prevent the escape oi' the lluid.

In testimony whereof I have allXed my I signature, in presence of two witnesses.

WILLIAM LE ROY BRYANT. Witnesses:

ROBERT l. FINN, F. P. LovnioY. 

